Tumor necrosis factor (TNF) antagonists for inflammatory bowel disease

Examples

How It Works

A tumor necrosis factor (TNF) antagonist is a type of antibody that inhibits tumor necrosis factor, a protein that increases inflammation in the body. Infliximab and adalimumab block the inflammatory response that happens in Crohn's disease and ulcerative colitis. They are both given as a shot. Infliximab is given as a shot in a vein (intravenous, or IV) and adalimumab is given as a shot under the skin (subcutaneous).

Why It Is Used

Infliximab was first used to treat abnormal connections (fistulas) between the intestines and organs in moderate to severe Crohn's disease. Now it is used to induce and maintain remission (a period without symptoms) in people who have Crohn's disease or ulcerative colitis that has not improved with other medicines.

Adalimumab is used to induce and maintain remission in people with Crohn's disease who have not improved with other medicines and who no longer respond to or cannot tolerate treatment with infliximab.

How Well It Works

Infliximab can induce remission in people with moderate to severe Crohn's disease, including the closing of fistulas. In one study, some people who were treated with infliximab had symptoms that came back after 3 months. It is now recommended that people treated with infliximab continue to get the medicine at regular intervals. This is called maintenance therapy.

In multiple studies, almost 70% of people taking infliximab had fewer symptoms or had healed fistulas.¹

In one study, between 60% and 70% of people with ulcerative colitis were better 8 weeks after getting infliximab treatment. In another study, twice as many people got better after receiving infliximab compared to those taking a placebo.²

Adalimumab has shown promise in treating Crohn's disease in multiple studies.³ It works like infliximab and may be good for people who are allergic to infliximab.

The long-term effectiveness of both medicines is still being studied.

Side Effects

Infliximab is given only in a vein (intravenously). Adalimumab is given under the skin (subcutaneously). Side effects include:

• Chest pain.
• Nausea.
• Fever.
• Chills.
• Itching (pruritus).
• Facial flushing.
• Headache.
• Rash.
• Fatigue.
• Dizziness.

Warnings about serious side effects of TNF antagonists have been issued. The U.S. Food and Drug Administration (FDA) and the drug’s manufacturers have warned about:

• An increased risk of blood or nervous system disorders, some potentially fatal. Contact your health professional if you have symptoms of blood disorders (such as bruising or bleeding) or symptoms of nervous system problems (such as numbness, weakness, tingling, or vision problems).
• An increased risk of a serious infection (such as tuberculosis). If you have had tuberculosis (TB) or know someone who has, tell your doctor. TNF antagonists also affect your body's ability to fight all infections, so if you are taking the medicine and get a fever, cold, or flu, let your doctor know right away.
• An increased risk of liver injuries, some potentially fatal. Call your doctor if your skin starts to look yellow, if you have dark brown urine or a fever, or if you are very tired.
• A possible increased risk of developing lymphoma (a type of blood cancer). It is not clear if this increase is because of the drug or because people with Crohn's disease may already have a higher risk.⁴ There have been reports of a rare kind of lymphoma, occurring mostly in children and teens taking TNF antagonists, that often results in death.
• A possible reaction to the shot. Some people will have hives, trouble breathing, or low blood pressure after an infusion of infliximab. Some people can have an allergic reaction to a shot of adalimumab. Signs of a serious allergic reaction include a skin rash, a swollen face, or trouble breathing. These reactions most often occur right away, and your doctor may give you medicines to prevent or stop the reaction.

What To Think About

Infliximab is more expensive than other medicines used to treat Crohn's disease.

This medicine is used for Crohn's disease and ulcerative colitis that has not improved (refractory disease) when treated with corticosteroids, aminosalicylates, antibiotics, azathioprine, or 6-mercaptopurine. Infliximab is recommended to be used when other medicines don't work.

The use of infliximab during pregnancy is still being studied. It may be used when other medicines have not worked and the health of the mother or of the fetus (or both) is at risk. It is not known if infliximab can pass from the mother to the baby in breast milk. If you have inflammatory bowel disease and you are pregnant, thinking about becoming pregnant, or breast-feeding, talk to your doctor about what medicines are safe for you to use.

Because adalimumab is given as a shot under the skin, you may be able to do the shots yourself after your doctor has shown you how.

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